SEV2c Ecological Succession

​Ecological Succession

Standard

SEV2. Obtain, evaluate, and communicate information to construct explanations of stability and change in Earth’s ecosystems.

c. Construct an argument to predict
changes in biomass, biodiversity, and complexity within ecosystems, in
terms of ecological succession.

Learning Target

I can explain how ecosystems

change over time.

• What happens to the

balance of nature
when a catastrophic
event such as a
volcanic eruption
happens?

• Can or will anything

survive?

Growth

Plants start to grow.

How do you think the
seeds get there?

Ecological Succession:

Changes in an
ecosystem that
causes older
organisms (if present)
to die out and new
ones to move in.

The last picture is the
climax community.
What do you think the
definition of climax
community is?

Multiple Choice

What is ecological succession?

• A slow change in an environment

• A change that happens quickly in an environment

• A change in abiotic factors only

• A state when an ecosystem doesn't change

Biomes

When we talk about
succession this is the
picture you usually see.

Think about the
organisms in different biomes. What do you
see as you follow the
arrows?

Think

What would be the
definition of a climax
community?

Multiple Choice

A climax community is ….

• the beginning of a new ecological succession.
• the rocks in a new environment.
• the fire that will cause destruction.
• an area that reaches its greatest growing potential.

Food Web

When we looked at
food webs the more
complex a food web
was the more stable
an ecosystem was.

Climax Community

Just like a food web,
each biome has
different organisms so the climax community will look different.

An ecosystem is always
trying to develop to its
most complex and
stable state.

Multiple Select

Which of the following shows a climax community?

There may be more than one.

Changing Ecosystems

Ecosystems constantly change. A tree
falling in a forest affects the forest
ecosystem. A fire might alter the forest
habitat so much that some species cannot survive and others can thrive.

The process of one community replacing another as a result of changing abiotic and biotic factors is called ecological succession.

Primary Succession

There is no soil and no
community to rebuild from

Common from volcanic
eruptions or newly formed
volcanic islands.

Common from newly exposed
glacial melt lands.

The first plants
on the scene to colonize an area are pioneer species.

What are their roles in ecological
succession? They initiate
recovery following a disturbance.

What are their role in primary
succession if any? They create soils.

Multiple Choice

A glacier retreats and exposes bare rock. What will occur next?

•  The rock will turn into soil

• A pioneer species will move into the area and begin to break down the rock into soil.

• A forest will grow in the area

• Grass will grow in the areaglag

Starting Primary Succession

Pioneer species secrete acids that help break down rocks. As
pioneer species die, their decaying organic materials mix with small pieces of rock. This is the first stage of soil development. Small weedy plants begin to grow in the soil. These organisms die, adding to the soil. Seeds brought by animals, water, and wind begin to grow. Eventually, enough soil forms to support trees and shrubs.

Multiple Choice

When lichens die what happens to them?

• They are blown away by the wind

• They decompose adding small amounts of organic matter to the rock to make soil

• They don't die

• Scavengers eat themlichen

Reorder

Reorder the following images showing the stages of primary succession.

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

What do you notice about the soil?

Multiple Choice

What is needed for more complex plants to grow?

• water depth

• soil depth

• wildfire

• complex food web

Community

Even though we look at
the plant community the
other organisms that live there are also changing.

Why would these
organisms change?

Multiple Choice

What animals would be the first to enter a new ecosystem?

• insects

• deer

• rabbits

• bears

Ecological Succession: Changes in an ecosystem that causes older organisms to die out (if present) and new ones to move in.

Glacial retreat, no soil, no community

Soil presence, recovering community

Take a moment to examine the image.
Is the order of sequence easily predicted?
How is this first stage different
from that of primary succession?

​Secondary Succession

What do you notice in this picture of succession?

Recovery Time

How long does it take for
an ecosystem to reach a
climax community in
primary succession?

What are the pioneer
species?

Recovery Time

How long does it take in
secondary succession?

What are the pioneer species?

What is different about the two timelines?

Multiple Choice

Why does primary succession take longer to reach climax community?

• Because trees do not perform photosyntheses.
• Because climax community is in a forrest.
• Because primary succession already has soil
• Because primary succession does not have soil

Multiple Choice

After a volcanic eruption, volcanic rock is present (but no soil). Which of the following states the most likely order of succession that would be seen?

• Lichens → Shrubs → Grasses → Trees

• Lichens → tree → shrubs→Grasses

• Grasses → Lichens → Shrubs → Trees

• Lichens → Grasses → Shrubs → Trees

Multiple Choice

A climax community is ….

• the beginning of a new ecological succession.
• the rocks in a new environment.
• the fire that will cause destruction.
• an area that reaches its greatest growing potential.

Multiple Choice

After an area was cleared for farmland 100 years ago, it has completely regrown large trees. This is an example of:

• Evolution

• Ecology

• Primary Succession

• Secondary Succession

Match

Match the following

Primary succession

pioneer species

abiotic factor

secondary sucession

climax community

• Primary succession

• pioneer species

• abiotic factor

• secondary sucession

• climax community

Multiple Choice

Which statement correctly describes a stage in the process?

• The grass stage is the most stable stage and has existed for thousands of years.

• The shrub stage modifies the ecosystem, making it more suitable for the pine forest.

• The pine forest stage has no biodiversity and the least competition.

• The hardwood forest stage will be replaced by a pine forest.

Multiple Choice

If farmers use a controlled burn to prevent forest fires, what would most likely be the first plants to return?

• trees

• shrubs

• mosses

• grasses

Multiple Choice

What are the pioneer species for secondary succession?

• Trees and shrubs

• Mosses and lichens

• Grasses and weeds

• Fruits and Vegtables

Multiple Choice

Which of the following is a characteristic of a habitat in the earliest stages of succession?

• Relatively low biodiversity

• Mostly hardwood trees

• Thick layer of rich soil

• High density of organic matter

Multiple Choice

What type of succession is shown going from figure A to figure B?

• primary succession
• ecological succession
• secondary succession
• intermediate

Multiple Choice

Which of the following events will most likely change the dominant plants in an ecosystem from large trees to grasses?

• High winds from a tornado.

• A brush fire from lightning.

• Flash flooding from storms.

• Overgrazing by herbivores.

Pond Succession

There is also succession
in ponds. This occurs as
sediment is washed into
the pond and it slowly fills
and turns into a terrestrial
climax community.

Open Ended

How are primary succession and secondary succession different?

Open Ended

How are primary succession and secondary succession the same?